Growing Tomatoes Ring Culture

[plantmark]

Considering growing tomatoes in the greenhouse using gravel trays with bottomless pots to save buying grow bags. Anyone else tried this?

[airconednightmare]

are you planning to fill the pots with soil or hydro based medium? either way the effectiveness of the gravel tray will depend on 3 factors: 1) you need to oxygenate the water 2) there needs to be sufficient (but not too many) nutrients in the water 3) some form of basic 'flood and drain' system will greatly improve the results.

you are basically (as far as i can tell) suggesting a primitive hydro setup in a greenhouse? if so search google for 'greenhouse hydroponics' and you should get most of the answers to soil free growing

[lazydog]

What would you achieve compared with ordinary growing just seems a load of hastle for no gain IMO

[airconednightmare]

Originally Posted by lazydog

What would you achieve compared with ordinary growing just seems a load of hastle for no gain IMO

theoretically, better supply of nutrients/oxygen/water to the roots means the plant(s) can put more effort into producing fruit

in terms of its ability to retain and consequently supply roots with optimum amounts of the aforementioned nutrient/O2/H2O mix, soil is actually about the worst thing to use

plus most hydroponic grow mediums can be reused with minimal environmental impact whereas repeated use and disposal of peat (used in just about every topsoil/compost/potting mix/etc) is non-renewable and stores C02 which is released when you dig it into your 'oh so eco friendly garden' (no offence specifically directed at yourself there, rather a discontent with certain trends expressed by the 'environmental movemeant' in general)

[plantmark]

Originally Posted by airconednightmare

are you planning to fill the pots with soil or hydro based medium? either way the effectiveness of the gravel tray will depend on 3 factors: 1) you need to oxygenate the water 2) there needs to be sufficient (but not too many) nutrients in the water 3) some form of basic 'flood and drain' system will greatly improve the results.

you are basically (as far as i can tell) suggesting a primitive hydro setup in a greenhouse? if so search google for 'greenhouse hydroponics' and you should get most of the answers to soil free growing

I was planning to fill the pots with Levington M2. In the trays I have baked clay granules. I wasn't planning to oxygenate the water (how would I do that?) Sounds like Grow Bags might be easier?

[airconednightmare]

you can put aquarium 'air stones' in the water and/or have some system kind of flood and drain setup (this won't actually oxegenate the water as such but will give the roots more O2. oh and H2O2 (hydrogen peroxide) in small amounts will both help keep the tank clean and further oxgenate the water as it breaks down into H2O and O2.

it requires pumps, timers, close attention to ph and nut levels and quite a bit of patience to get it working well. so yes grow bags are easier but ultimately less productive and more environmentally damaging

[plantmark]

It could be said that a grow bag is similar to the tray of gravel, in that if we make a slit half way up the side as suggested on the bags, the bag can half fill with water to give the same effect as the tray of gravel in that the roots will be submerged?

[airconednightmare]

don't growbags have small holes to allow excess water to drain out?

having roots permanently submerged in 'stale' (non-moving & therefore un-oxygenated) water isn't good for those roots and consequently the plant in general. assuming some of the roots (those in the soil/above the water level in the tank) have access to air then the plant will grow.

however i see 2 issues with this: 1) the plant won't have a better supply of O2/H2O/nuts and therefore may as well be in just soil 2) the water/nut mix and ph levels in the tank will still require close attention but without the superior harvest which would normally justify the extra time and effort.

simply pumping air into the tank will greatly improve the results

[jackb]

I have grown hydroponic tomatoes in the greenhouse for several years. In past years I have used expanded clay pellets as a medium in a flood and drain system. The last two years I have used autopots with coco coir and perlite for tomatoes and cucumbers. In the photo below the toms are on the right and the large tank at the back of the greenhouse contains the nutrients. Each tray has a float valve which automatically feeds the plants. Once planted there is very little maintenance.

More photos of hydroponic systems are on my blog if you have an interest.

Hydroponic Workshop

Jack

[plantmark]

A great setup Jack. What are the results like? Must be expensive to setup?

[jackb]

Originally Posted by plantmark

A great setup Jack. What are the results like? Must be expensive to setup?

The autopot double trays are made in the UK so they may be less expensive there; here they cost about fifty dollars per set. I have purchased a set each season for the last several years, and my son gave me two sets. Any container can be used as a reservoir. All you need is a top hat grommet which costs under a dollar. They do a great job on toms and cucumbers, as the moisture level is pretty much constant. Depending on how fast the plants are growing determines how often I have to replenish the reservoir. Usually it is every week or so. My toms, cucumbers and peppers are flowering already, and it is only mid-April. In my part of the world we are still six weeks away from being able to set plants outside.

Jack

[jackb]

Originally Posted by plantmark

A great setup Jack. What are the results like? Must be expensive to setup?

If you would like to see the results; here is photo taken today, May 1, 2010. The third trusses are forming and the first trusses have set fruit. The photos are less than two weeks apart I think. I am very satisfied with the results so far.

[plantmark]

Superb looking plants Jack !

[jackb]

I did not even have flowers until June last season.
Perhaps my luck is changing, or I am getting the hang of greenhouse culture.